Technical data

CHAP-04.10 ELECTRICAL POWER DISTRIBUTION, DRIVES, CONTROL &
ILLUMINATION ELECTRICAL
Page 29 of 50
sides for power supply to solenoid valves.
d) Auxiliary contactor for control power supply monitoring
interlocking, and controls etc.
e) Auto-manual selector switches, push button switches, indication
lamps, various monitoring devices, terminals (with 20 percent
spare terminals) and other circuit elements required for control
and monitoring
f) Solid State Bag filter timers.
02 The bag filter timer will be solid state device suitable for dusty,
tropical and specified aggressive environment. The bag filter- timer
will be provided with internal semi-conductor fuse protection and will
have provision for pulse frequency setting and pulse duration setting
through independent operating knobs. The number of contacts in the
timer will be equal to number of solenoid operated valves so that the
timer will energise only one solenoid valve at a time.
03 The Bag Filter Timer will provide timed sequential energisation of
24V DC operated solenoid valves of bag filters LEDs for each
solenoid energisation. Power ON in PCB feed back relay will be
provided with potential free contacts which will close under following
conditions:
i) Fault in the PCB.
ii) Open contact in the output side connected to individual solenoid
valves. The contact will not close in the event of power failure to
the controller.
iii) The sequential control (i.e. process) will start when the Differential
Pressure (DP) switch is actuated at the first set point for normal
operation. The process will continue till the pressure differential
drops below the set value. When again the DP switch is actuated
the process will continue from the previous position (i.e. next
solenoid valve). However, when the power supply to sequential
controller trips, the process will stop and sequential controller is
reset to first load position enabling the process to start from the
beginning.
iv) Sufficient space will be provided for installation of bag filter panel
with required front clearances for operation and maintenance
including side and back clearances as required.
04 Differential Pressure Switch
i) The differential pressure switch will have two sets of independent
micro switches. The first set will be used for normal sequential